1. Field of the Invention
The field of this invention is within the audio alarm field. More specifically, the field of the invention resides within the telephone field as it relates to ringers and audible alarms for telephones.
2. The Prior Art
The background of the invention is such that it falls within the general telephone art as evolved over the years. It is customary to ring a prospective recipient of a call by means of having a buzzer alarm, or more generally, a mechanical ringer sound an alarm that the telephone subscriber or recipient is being called.
The recipient of a call in times past has been apprised of a call by means of applying an alternating current on the line connected to the recipient's telephone. This causes a mechanical ringing of a bell. The alternating current can be provided in numerous ways. Initially, it was provided by a hand crank turning a generator which allowed for the ringing to take place. However, recently, the utilization of alternating current provided from the central office imposed on the direct current on the line has been the accepted method of causing a ringer of the recipient to function.
In effect, a prospective recipient or subscriber of a telephone call is apprised of the fact that a call is being placed by means of alternating current originating from the central office in response to the switching network being actuated through the caller's dial or touch tone actuation who is originating the call.
The recipient of the call generally has the ringing take place within his telephone set. The ringing is caused by a bell which is implaced within the telephone set. The bell has a rotating or moving clapper that moves in response to the energization of a coil. The coil, of course, is energized by the AC in a duty cycle consistent with a desired ringing. The duty cycle can either be one second of ringing and three seconds off or two seconds of ringing and four seconds off, etc. Regardless of the duty cycle, the ringing takes place in response to the AC imposed on the line.
Recently, it has been customary to provide a subscriber or user of a telephone with a telephone that can be connected to multiple jacks throughout the building. In other words, the subscriber has a telephone line coming into his building connected to a series of jacks that can connect his telephone to a line connected to the central office. The tip and ring sides of the line, or the plus and minus side respectively of the jacks can be used for either plugging the telephone directly thereinto, or a ringer at particular jack locations. In other words, the telephone can be implaced in one particular location of the house or building and the ringer in another location. This allows flexibility so that ringing can take place in various locations, as well as allowing a telephone receiver to be implaced in various locations of the house.
Utilization of mechanical ringers for such purposes has been cumbersome at best. This is due to the fact that mechanical ringers are substantially bulky. Furthermore, mechanical ringers are known for their spurious bell tap noises. In other words, when a subscriber dials his phone, sometimes the bell will ring inadvertently on a tapping or mildly ringing basis. This is undesirable and tends to bother some subscribers. Additionally, mechanical ringers must be established with a certain degree of mechanical controls to provide certain ranges and degrees of loudness. This is sometimes difficult.
The instant invention overcomes not only the foregoing deficiencies, but also provides a solid state ringer that is substantially wear resistant and does not have any moving parts other than the speaker or transducer. As can be appreciated, a solid state electrical device is generally superior to a mechanical device in providing long range durability and service. Thus, the great number of service calls that are associated with mechanical ringers and mechanically operated telephones may be eliminated. Inasmuch as the telephone companies are moving more and more to solid state electrical devices, a solid state ringer is very compatible therewith.
To date, certain effects have been embarked upon in order to provide solid state ringers. Such efforts have not met with success. They usually involve a situation wherein an oscillator is connected to a telephone line.
Such oscillators are generally not maintained at a proper level for effective oscillation, or the lack of current regulation creates inordinate or irregular ranges or operation. They are often irregular in their operation and it is difficult to correct the disparate way in which they operate.
This invention solves the long felt need of a solid state ringer. It also effectively meets the standards of a telephone network to prevent bell tap as well as allow for a ringing on a consistent basis through an audio signal generated by a speaker driven in the manner to be described hereinafter. Furthermore, it does not unduly interfere with the stability of the telephone network into which it is connected.